< Back to previous page

Project

Hygrothermal creep behaviour of natural fiber composites

  Natural fiber composites (NFC) are considered as an effective supplement or even alternative to synthetic fibers as reinforcement for composite materials in many industrial applications such as construction, automotive, and marine industries. In these applications, NFC are often exposed in hygrothermal environment over an extended period of time, which can cause the severe degradation of their mechanical properties such as creep behavior which is a major concern with respect to long-term durability. In general, a composite material consists of three phases (fibre, matrix, and interphase). The mechanical properties of each phase could affect the overall mechanical performance of composites. When exposed to hygrothermal environment, the creep resistance of NFC usually decreases with the aging of its constituents, e.g. the swelling of the fibre, forming voids and micro-cracks at the fibre-matrix interface region. Therefore, it is of great necessity to investigate the creep behavior of the components of NFC under hygrothermal aging condition as well, with respect to their contribution to the macroscopic response. Among the three component phases, the fiber-matrix interface is a key element which to a great extent determines the creep behavior of composites, since stress transfer and load distribution efficiency at the interface is determined by the degree of adhesion between the components,and poor interfacial adhesion can cause larger creep deformation than expected even if both the fiber and matrix have good creep resistance. In addition to this, the thin interface region is inherently viscoelastic despite its creep deformation is trivial compared to the other two components. Hence, the first objective is to investigate the effect of interface properties on the overall creep behavior of NFC. Then a micromechanics creep model will be proposed to relate the macroscopic creep response of NFC to its three constituents for purpose of design and optimization of composites.

Date:22 Feb 2021 →  Today
Keywords:composites, creep
Disciplines:Natural and biocomposites
Project type:PhD project